Timing apparatus for clocks and watches



Jan. 26, 1954 T. B. GIBBS TIMING APPARATUS FOR CLOCKS AND WATCHES Filed June 24, 1948 INVENTOR. THOMAS B. G/BBS BY MK2/m ATT'Y Patentecl Jan. 26, 195,4

UNITED STATES RATENT OFFICE TIMING APPARATUS FOR CLOCKS AND WATCHES Thomas B. Gibbs, Delavan, Wis.

Application June 24, 1948, Serial No. 35,043

14 Claims. (Cl. 'Z3- 6) The present invention relates in general to timing apparatus for clocks and watches, and more in particular to apparatus forvtiming and regulating the rate of the balance wheel of a clock or Watch before it is assembled with the rest of the movement. It is the usual practice in the art to regulate the rate of a balance wheel by adjusting the length of the associated hairspring while the balance wheel is oscillating or vibrating and the operation is commonly referred to as hairspring vibrating.

Apparatus for hairspring vibrating as referred to in the foregoing is disclosed in the patent to Gibbs et al., No. 2,231,849, granted February 11, 1941. As disclosed in this patent, a balance wheel to be timed and regulated is temporarily supported in suitable bearings and is oscillated by hand, that is, it is started by hand and is a1- lowed to oscillate ireely at its natural frequency, the oscillations continuing long enough to permit the hairspring to be adjusted. Or the balance wheel may be restarted one or more time if necessary. f

The invention is directed to an improved form of apparatus in which a balance wheel being timed is positively driven by impulses or puffs of air. The balance wheel is started by a strong air impulse, suciently powerful to initiate oscillation of the Wheel at substantially full amplitude, and is then driven by so-called running impulses which are generated in response to oscillation of the wheel. These running impulses have a frequency which is one-half the beat frequency of the Wheel, and drive the wheel While it is moving in one direction only, giving rise to a diiiiculty in coordinating the start of the running impulses with the motion of the-wheel acquired in response to the starting impulse. The invention solves this Aproblem and provides means for starting the wheel and for automaticallystarting the running impulses in phase with the wheel.

The invention will be described more in detail in the following specification, reference being had to the accompanying drawing, which shows diagrammatically the circuits and apparatus of a hairspring vibrating installation embodying the invention.

Referring to the drawing, the reference character lil indicates a balance wheel having a hairspring Il, which is to be tested and adjusted. The balance wheel is supported on a` suitable stand (not shown) having bearings for the balance wheel arbor so arranged that'the wheel can be quickly placed in position'and removed. The end of the hairspring is clamped between the 2 two rollers l2 and I3, one of which is manually rotatable to feed the hairspring in and out to adjust its effective length. A stand such as described is well known and will require no further explanation.

The apparatus for generating and delivering air impulses to the wheels includes the supply pipe l5 which is connected to a suitable pump and reservoir system for supplying compressed air at constant pressure, with means for regulating the pressure to a value which is suitable for starting the wheels.

The strong starting impulses are generated by means of the valve I6, operated by the electromagnet l l, and are delivered to the wheels by the nozzle E8. The running impulses are generated by the valve IQ, which is operated by the electromagnet 2B. The running impulses are delivered by the nozzle 2i and are weaker than the starting impulses, due to the interposition of the reducing valve 22 in the branch supply pipe leading to valve I9. The reference character 23 indicates a surge tank.

A suitable source of light is indicated at 25, while 25 indicates a lens or optical system arranged to project a light beam on to the rim or" a balance wheel such as the wheel IB. The photocell 2l is so located that it intercepts the reflected beam and generates electrical voltages responsive to the movement of the Wheel, as eX- plained in Patent No. 2,231,849, previously referred to.

The output of the photo-cell 2 is transmitted by way of the condenser 2s to an amplifier, represented by the rectangle 28, which may be of any known and suitable construction,

The tube 3| may be a type 6F6 pentode and has its control grid coupled to the amplifier 28 by means of the condenser 36 and the volume control potentiometer 32.

The reference character 33 indicates a transformer, the primary winding of which is included in the plate circuit of tube 3i. The secondary windings of the transformer are connected in a direct current circuit which includes the full wave rectifier tube 3Q and the load resistor 35. The tube 34 may be a 6X5G tube. A voltmeter 36 is provided to indicate the voltage developed across the resistor 35.

The tube 38 may be a type 884 Thyratron tube,

connected as shown. It Will be noted that the control grid of the tube is connected to the negative end of resistor 35, at junction 3l.

The tube e3 is preferably a type 631P1 Strobetron tube, and forms part of a stroboscopic indi- 3 is disclosed in the patent to Gibbs, No. 2,361,281, granted October 24, 1944. This indicator includes a drum rotating at constant speed and provides a light spot which by its movement to the right o'r left indicates whether a balance wheel being tested is fast or slow.

The tubes 5G and 5I may be type 884 Thyratron tubes and are connected in a known circuit arrangement whereby they fire alternately in response to successive impulses received from tube 33 over conductor 14. The grids of the tubes have a iixed negative bias as indicated at 53 and the plates o1" the tubes are connected by the condenser 52.

The tube S6 may be a type 6N7 double triode and is wired according to a known circuit arrangement for operation as a delay device. It receives impulses through condenser 6i from tube :'i and transmits each impulse after a short time delay to the grid of tube 10 by way of condenser E3. The length of the delay can be adjusted by means of the potentiometer 64.

The tube 10 may be a type 2050 Thyratron tube and controls the circuit of the electro-magnet 2i! associated with the air valve I9. The tube has a negative grid bias, as indicated at 1 I.

The operator is provided with a key K for controlling the apparatus. This key may be a telephone type key and has two positions, a normal or stop position, the position in which it is shown, and an operated position, or start position. The key is not self-restoring, that is, when operated it remains in operated position until restored by the operator.

The relay 12 is controlled by the key K and operates as a timing device to start the delivery of running impulses at the proper time with relation to the starting of a wheel to be tested, as wili be explained presently.

The apparatus includes the necessary means or supplying current for operating the tubes and other equipment and the switches for turning the current on and off, as will be understood.

The operation of timing a balance wheel will now be described. For this purpose it may be assumed that the switches are closed, and that the compressed air apparatus is in operation, delivering compressed air under the proper pressure to the supply pipe I5.

When the current is turned on, the condenser i0 associated with the tube 38 charges in series with the plate resistor 4I and the voltage on the plate of the tube accordingly rises until the tube lires. The condenser 40 then discharges through the tube, causing the plate voltage to drop to such a low value that the tube is extinguished. The condenser il@ then charges again and the action is repeated. The values of resistance and capacity are such that the tube 38 fires at a fre- G ueney which is preferably about double the beat frequency of the balance wheels to be timed.

Each time the tube 38 fires, the potential on its cathode rises suddenly, due to the drop across the cathode resistor 39, and a positive impulse is transmitted by way of condenser 42 to the control grid of the Strobotron tube 63 o the indicator. These positive impulses control tube i3 in known manner. That is, the tube res on each impulse and is extinguished quickly each time by the discharge of condenser 35. The ashes thus produced are seen by the operator as the spot of light previously referred to and show that the indicator is in working order.

The tube 38 also transmits impulses by way oi conductor Q4 and the condensers 54 and 55 to cator such as the grids of tubes 50 and 5 I, which start ring a1- ternately on successive impulses. The operation is well known and need not be explained in detail. Each time the tube 50 fires a positive impulse is transmitted to the delay device which includes the tube 60 and this device transmits delayed impulses to the grid of tube 10. The impulses have no effect, however, because the grid of tube 10 is grounded by way of contact 14 of the key K. The operation of the delay device will be explained more fully later on.

A balance wheel such as I0 may now be placed in position on the stand, with the free end of the hairspring clamped between the rollers I2 and I3. Having seen to it that the balance wheel is free to oscillate, the operator will operate the key K, moving it to start position, thereby closing contacts 15 and 16 and opening contact 14.

The condenser 11 has become charged through the resistor 18 and upon the closure of key contacts 16 the condenser discharges through the electro-magnet I1. The electro-magnet I1 accordingly energizes and opens the air valve I6, thereby delivering a strong starting air impulse to the balance wheel I0, which sets the wheel in motion in a clockwise direction. Although contact 16 remains closed, for the time being, the valve I6 is only momentarily operated, the electro-magnet I1 de-energizing following the discharge of condenser 11, because of the high resistance of resistor 18. The capacity of the condenser 11 is so related to the impedance of the electro-magnet I1 and the power required to operate the valve I6 that a very substantial and somewhat prolonged air impulse is given to the wheel, sufficient to start the wheel oscillating at approximately its normal amplitude.

The condenser 19 has also become charged, by way of resistor 80, and upon the closure of key contacts 15 the condenser discharges through the relay 12. Upon energizing, relay 12 closes its contact 13 and thus grounds the plate of tube 50, which extinguishes the tube if it should happen to be fired at the time relay 12 is energized. Relay 12 cannot remain operated in series with the resistance and falls back after the condenser 19 has become substantially discharged. The capacity of condenser 19 is so related to the other characteristics of the circuit that relay 12 remains operated and keeps the plate of tube E!) grounded for about one full beat. The reason for this arrangement will appear later on.

The opening of key contact 14 removes ground from the grid of tube 10. The condenser 8l has become charged and the full B supply voltage is applied to the plate of the tube but the tube does not fire because of the negative bias on its grid.

When the balance wheel I0 is set in motion by the starting air impulse, certain variations are produced in the current which flows through the photo cell 21. The photo cell current is responsive to light reflected from the rim of the wheel and the variations are due to movement of the Wheel beneath the impinging light beam. Thus, current variations are produced while the wheel is in motion, which cease when the wheel stops to reverse its direction of movement.

The photo cell currents are amplified by the amplier 28 in known manner and a varying vvoltage is developed across the winding of the potentiometer 32. This voltage, or a selected portion thereof, is delivered to the grid of the tube 3l and causes variations in the current in the plate circuit of the tube, said circuit including the primary winding of the transformer 33.

vVoltages are thereby induced in the secondary make one half beat in a clockwise direction, or

at least approximately one half beat. During this movement of the wheel a negative potential is produced at junction 31 in the manner described, and since the junction 31 is connected to the grid of tube 38, the negative potential prevents the tube from firing. The interval of one half beat during which tube 38 is thus held under control is long enough to enable condenser 48 to become charged, in case tube 38 should have red just before the wheel was started.

When the wheel stops to reverse its direction of movement, the generation of varying photo cell currents ceases and the potential at junction 3'! falls to zero. The negative potential at the grid of tube 38 being thus removed, the tube fires in the manner previously described and transmits a positive impulse over conductor 44 to the grids of tubes 50 and 5|. Tube 58 is inoperative at this time due to its plate having been grounded by relay 12. Tube 5| fires responsive to the impulse received over conductor 44.

The wheel now makes one full beat in a coun terclockwise direction. Throughout this beat the movement of the wheel produces a negative pctential at junction 37 and at the grid of tube 38, which prevents the tube from firing.

At some point during this counter-clockwise beat, preferably about midway during the beat, relay 'I2 de-energizes and removes ground from the plate of tube 50, thus preparing the tube for ring on the next impulse from tube 38.

At the end of the counter-clockwise beat the wheel stops again, the potential at junction 31 falls to zero, and the tube 38 res again, thereby transmitting another impulse over conductor 44 to the grids of tubes 50 and 5l which now causes tube 50 to fire. When tube 50 res, the plate potential drops sharply, whereby a negative impulse is transmitted by way of condenser` 52 to the plate of tube 5l and the latter tube is extinguished. Tubes 50 and 5| continue to re alternately responsive to successive impulses from tube 38, now firing at beat frequency under control of the wheel.

The wheel now makes a full beat in a clockwise direction, the direction in which it is rotated by the starting impulse. About the middle of this beat it is given a running impulse of air by opening valve I9, which is responsive to the ring of tube 3S at the end of the first counter-clockwise beat as will now be explained.

When tube 38 fires 1t causes tube 50 to re, as already described. When tube 58 res, the potentiai on its cathode rises suddenly, due to the drop across the cathode resistor, and a positive impulse is transmitted to grid B of tube 60 by way of the condenser Eil.

The two sections of tube 63 are referred to herein as sections A and B respectively, and the grid and plate elements likewise. Section A is normally passing current, grid A being connected to the cathode. Grid B is connected to ground and the positive potential on the cathode due to current flow in section A produces a negative bias on grid B, which prevents section B from passing current. This is a stable condition, in which condenser 65 becomes charged to substantially the potential of the -B lead.

When the positive impulse is received at grid B from tube 58, section B starts to pass current and the potential on plate B drops suddenly, driving grid A negative due to the charged condition of condenser 65. The fall of potential at grid A decreases the current flow in section A, which causes the potential at plate A to rise. The rise of potential at plate A raises the potential on grid B, due to the coupling through condenser 62, which increases the current flow in section B and causes a further drop in potential at plate B. Thus, a kind of regenerative action takes place whereby the voltage at plate B falls very quickly to a low value` and the grid A attains a negative potential which biases section A to cut-01T.

The condenser 65 now starts to discharge through section B of the tube and the potential on grid A gradually rises toward the cathode potential. When the grid potential reaches a high enough value so section A can begin to pass current, the regenerative action is repeated and the tube returns quickly to its original condition, in which section A is conductive and the grid of section B is biased to cut-01T.

The cessation of current flow in section B of tube B produces a sudden rise in potential at plate B, thereby transmitting a positive impulse through condenser 63 to the control grid of the Thyratron tube 10, causing this tube to fire. The firing of tube 10 causes the condenser 8i to discharge in series with the tube and the winding of the electro-magnet 20. This gives a short powerful energization of the electro-magnet and at the same time extinguishes tube 70, owing to the high resistance of resistor 82. The condenser 8| charges up again through the resistor.

The energization of the electro-magnet 20 opens the air valve i3 momentarily, thereby delivering an impulse of air to the wheel I0. This isthe running impulse just referred to, which is given to the wheel at about the middle of the rst full beat in a clockwise direction. The air impulse is responsive to the ring of tubes 38 and 50 at the end of the rst counter-clockwise beat, but sucient delay is introduced at tube 58 so that the air impulse is delivered to the wheel at about the middle of the succeeding clockwise beat, as stated. The amount of delay /required depends on the operating time of the electro-magnetic valve mechanism {Q -2i] and can be adjusted to the proper value by means of the potentiometer 64.

At the end of the beat the tube 38 res again, firing tube 5I and extinguishing tube 50.

The wheel now makes the second counterclockwise beat. At the end of the beat tube 38 res again, firing tube 58 and extinguishing tube 5i. Tube 50 transmits an impulse to the delay device 60 which in turn transmits an impulse to the Thyratron tube at the proper time to energize electro-magnet 20 again and give the wheel another running impulse during the next clockwise beat. The operation continues in this manner, the wheel running free during each counterclockwise beat and receiving a running impulse during each clockwise beat. The running impulses should have the right amount of power to maintain the oscillation of the wheel at the proper 7 amplitude and can be adjusted as to power by means of the reducing valve 22.

When the oscillating balance wheel takes over control of the tube 38, the impulses which this tube transmits to the Strobotron tube 43 of the indicator are transmitted at the beat frequency of the wheel and by watching the indicator the operator is able to tell whether the wheel is fast or slow. In practice the hairsprings are always made too long, so the wheel will be slow. The operator accordingly shortens the eiective length of the hairspring by rotating the roller i3, and cuts off the spring when the adjustment is correct as shown by the indicator. This regulating operation is well known and will require no further explanation.

The key K is restored as soon as the wheel has been timed and regulated. The restoration of the key grounds the grid of tube T0, which stops the operation of the running air valve i9. rhe restoration of the key also disconnects the magnet Ve' and relay 'l2 from the condensers 'i1 and 19, respectively, and permits these condensers to charge preparatory to the starting of another wheel.

The wheel which has just been regulated may now be removed and replaced by another wheel to be timed and regulated, whereupon the key K is again moved to its start position and the operations described are repeated.

The invention provides an arrangement for starting the balance wheels which is very reliable and which saves time by starting the wheels en at substantially full amplitude. The operators work is simplified, moreover, since the control key has only two positions and the starting of the running impulses is accomplished automatically at the proper time after the key has been moved to start position and the initial starting impulse has been given to the wheel.

The invention having been described, that which is believed to be new and for which the protection of Letters Patent is desired, will be pointed out in the appended claims.

I claim:

l. Apparatus for regulating the rate of a balance wheel and hairspring, comprising means for supporting a wheel for oscillation, means including a manually operated switch for delivering a starting impulse of air to said wheel to start the same, means responsive to oscillation of said wheel for generating an electrical impulse each time the wheel stops to change its direction, means for generating running air impulses responsive to the odd electrical impulses, means including a timing device started by operation of said switch foi` preventing generation of a running air impulse responsive to the first of said electrical impulses, and means for comparing the frequency of said electrical impulses with a standard frequency.

2-. Apparatus as claimed in claim l, wherein the timing device comprises a condenser which is charged while said switch is in normal position, and a relay energized by discharge of said condenser when said switch is operated.

3. In an apparatus for regulating the rate cf a balance wheel and hairspring, means for supporting a wheel for oscillation, means including a manually operated switch for delivering a starting impulse of air to said wheel to start the same, said means also including electromagnetic air impulse generating mechanism and a circuit for said mechanism closed by operation of said switch, means responsive to oscillation of said Y wheel to generate an electrical impulse at the 8 wheel for delivering running air impulses to said wheel, and timing means responsive to the operation of said switch for starting the delivery of said running impulses in phase with the wheel.

4. Apparatus as claimed in claim 3, wherein the timing means includes a condenser, and a relay, the energization of which depends on the charge in said condenser.

5. In an apparatus for regulating the rate of a balance wheel and hairspring, means for supporting a wheel for oscillation, means including a manually operated switch for delivering a starting impulse of air to said wheel to start the same, means responsive to oscillation of said wheel for delivering running air impulses to said wheel, means comprising a timing device started by said switch for automatically measuring a time interval beginning with the starting of said wheel, and means controlling said running air impulse means and operable in response to said timing device to delay the start of said running impulses until said time interval has expired.

6. In an apparatus for regulating the rate of a balance wheel and hairspring, means for supporting a wheel for oscilaltion, a manually operable switch having start and stop positions, means responsive to movement of said switch to start position for delivering an impulse of air to said wheel to start the same, means responsive te oscillation of said wheel for delivering running air impulses to said wheel, and means operating automatically while said switch remains in start position for causing said running impulses to be started in phase with the wheel, said last means including a device for preventing the delivery of the first running impulse until the wheel resumes its motion in the same direction as the direction in which it was started.

7. In an apparatus for timing a balance wheel and hairspring, means for supporting a balance wheel for oscillation, two nozzles for delivering air impulses to said wheel, an operators switch, means responsive to the actuation of said switch for delivering a strong starting impulse to said wheel through one nozzle, including means for preventing the delivery of more than a single starting impulse responsive to such actuation, and means responsive to the oscillation of said wheel while said switch remains in actuated position for delivering relatively weak impulses t0 said wheel through the other nozzle.

8. n an apparatus for timing a balance wheel and hairspring, means for supporting a wheel for oscillation, pneumatic mechanism for delivering air impulses to said wheel, an operators key, electromagnetic means responsive to actuation of said key to operate said mechanism to deliver a strong impulse oi air to said wheel to start the same, means responsive to the oscillation of said end of each beat, means responsive to alternate electrical impulses to operate said mechanism to generate light running air impulses to drive said wheel, said running impulses having a frequency equal to one half the beat frequency, means responsive to the said actuation of said key to insure that the nrst running impulse is generated responsive to the second electrical impulse and at a time when the wheel is moving in the same direction it moved in response to the starting impulse, and means operative to introduce a time interval between each electrical impulse and the running impulse responsive thereto, said intervals being of the proper duration to cause the running impulses to be delivered to the wheel in such timed relation to its motion that the wheel is eiiiciently accelerated by each running impulse.

9. In an apparatus for timing a balance wheel and hairspring, means for supporting a balance wheel for oscillation, mechanism for applying air impulses to said wheel, an operators key, means responsive to actuation of said key to operate said mechanism to start said wheel, means responsive to oscillation of said wheel for generating a, series of electrical impulses of beat frequency, means responsive to alternate impulses of said series for operating said mechanism, a relay and circuit controlled thereby for controlling the response of said last means to said impulses, and means also responsive to the actuation of said key to produce an operation of said relay to control said circuit and cause said impulse responsive means to start its response with the second impulse of said series.

10. In an apparatus for timing a balance Wheel and hairspring, means for supporting a balance Wheel for oscillation, mechanism for applying air impulses to said wheel, an operators key, means responsive to actuation of said key to operate said mechanism to start said wheel, means responsive to oscillation of said Wheel to generate a series of electrical impulses of beat frequency, a pair of space discharge devices arranged to re alternately responsive to impulses of said series, means responsive to each firing of the rst one of said devices to operate said mechanism, a relay and a circuit controlled thereby effective to render the rst said device incapable of ring, and means responsive to the said actuation of said key to produce a momentary operation of said relay extending from a time prior to the generation of the nrst impulse of said series to a time between the generation of the lst and second impulses of said series, whereby the rst said device is prevented from nring on the said rst impulse of said series.

11. In an apparatus for timing a balance wheel and hairspring, means for supporting a balance wheel for oscillation, mechanism for applying air impulses to said wheel, means responsive to oscillation of said wheel for operating said mechanism, said last means including a space discharge device, an operators key, a circuit including contacts of said key and effective to render said device inoperative when said key is in normal position, and means responsive to actuation of said key for operating said mechanism to start said wheel, said circuit being effective upon restoration of said key to stop said wheel.

12. In an apparatus for timing a balance wheel and hairspring, the combination of, a support adapted to mount a balance wheel for oscillation about its axis, a valve adapted when opened to deliver to a wheel on said support a starting impulse of gas under pressure of a predetermined magnitude suicient to overcome the inertia of the Wheel when the hairspring thereof is 10 deenergized and to oscillate the wheel substantially through its full range from a position of rest, a manually operated switch, means operable in response to actuation of said switch to open said valve long enough for delivery of said starting impulse and then close the valve, a second valve adapted when opened to deliver to said Wheel a running impulse of gas under pressure of a magnitude less than said predetermined magnitude, and means operable after the delivery of said starting impulse and in timed relation with oscillations of said wheel to open said second valve periodically for the delivery of a succession of said running impulses in phase with the wheel.

13. In an apparatus for timing a balance wheel and hairspring, the combination of, means adapted to support a balance wheel for oscillation about its axis, mechanism adapted when activated to deliver an impulse of gas under pressure against a wheel on said supporting means for turning the wheel about its axis, a manually operated switch, means operable in response to actuation of said switch to activate said mechanism for delivering to said wheel a single starting impulse of predetermined magnitude sufficient to overcome the inertia of the wheel and oscillate the latter substantially through its full range from a position of rest, and means operable in response to oscillations of said wheel and after delivery of said starting impulse to activate said mechanism for delivering to the wheel a succession of running impulses in phase with the oscillations thereof and of substantially constant magnitude less than said predetermined starting impulse magnitude.

14. In an apparatus for timing a balance Wheel and hairspring, the combinaton of, a support adapted to mount a balance wheel for oscillation, meansoperable when actuated to deliver to a wheel on said support an impulse of gas under pressure, an electrical network operable in response to oscillations of said wheel to generate an electrical impulse each time the Wheel stops to reverse its direction of rotation, and means responsive to alternate ones of said electrical impulses and operable to actuate said gas delivery means in timed relation to the alternate electrical impulses to deliver a succession of gas impulses to said wheel in phase with the oscillations of the wheel.

THOMAS B. GIBBS.

References Cited in the iile of this patent UNITED STATES PATENTS Number Name Date 2,086,391 Poole July 6, 1937 2,330,416 Gibbs Sept. 28, 1943 2,332,587 Mendelsohn et al. Oct. 26, 1943 2,358,078 Kohlhagen Sept. 12, 1944 2,360,053 Gibbs Oct. 10, 1944 2,423,985 Kohlhagen July 15, 1947 2,624,194 Wickham Jan. 6, 1953 

